Solid state disks (SSD) have faster read/write speed than conventional hard disk drives (HDD). Compared with the conventional HDD, the SSD has many advantages such as having no mechanical read/write heads, being more endurable against external impacts/collisions, having less noise and generating less heat. With rapid development of the semiconductor technology, the SSD offers a high storage density at lower costs. Consequently, server industry has a tendency to use SSD instead of HDD for massive data storage.
In order to boost the performance of the SSD, which includes improving TOPS (i.e. input/output operations per second) speed and work performance among processors, platforms and applications, a non-volatile memory express (NVMe) protocol is developed. An NVMe card is developed based on flash memory, and the NVMe card works with the SSD better than an advanced host controller interface (AHCI). Therefore, the NVMe card greatly reduces latency between a controller and a software interface, and optimizes the performance of the solid state disks using SATA (i.e. serial advanced technology attachment).
In the server industry, the NVMe cards are costly and typically have two different card sizes, so an insertion slot in a server chassis also has two different sizes. When the NVMe card is inserted to a wrong insertion slot, the NVMe card is often damaged by the wrong insertion, leading to unnecessary high maintenance costs. In views of this, in order to solve the above disadvantages, the present inventor studied related technology and provided a reasonable and effective solution in the present disclosure.